Electron discharge device



June 1954 F. E. GEHRKE ELECTRON DISCHARGE DEVICE Filed Feb; 1, 1949 INVENTOR.

Attorney Patented June 1, 1954 2,680,208 ELECTRON DISCHARGE DEVICE Forrest E. Gehrke, St. Albans, N.

Sylvania Electric Products of Massachusetts Application February 1, 1949, Serial No.

Y., assignor to Inc., a corporation 14 Claims. (01. 313293) The present invention relates to electron discharge dev1ces, and more particularly to an imdischarge tubes.

An object of the present invention is to improve the operation of high frequency electron discharge tubes.

Another object of the present invention is the provision of an improved grid structure for electron discharge tubes.

Still another object of the present invention is readily constructed, while at the same time being sturdier than previously known grid structures.

Still another object of the present invention is the provision of a grid structure for electron discharge tubes in which space is at a premium,

grid still being able to absorb large mechanical shocks without change in electrical characteristics of the tube into which it has been placed.

The present invention particularly relates to an improved form and method of manufacture of a half grid structure.

that either of the previously known types of half grids have several serious disadvantages. using grid lathes of the type heretofore known, which employ the swaging method of fastening creased from two side rods and a length of lateral wire wound around them, to as many parts as there are laterals in addition to the two side rods. Thus considered as mechanical construcgrids as manufactured by pre viously known methods are very flimsy.

with an aspect of the present in it 1s proposed to manufacture half grids by winding 2. regular two side rod grid of the kind normally used in radio tubes and then press ing the laterals on one side of the grid in upon the other side. After all of the laterals have been pressed into the same plane, the form or shape the required elevational view an elecemploying the present in- Fig. 4 is a side view of the grid shown in Fig. 3.

Fig. 5 is an end view similar to Fig. 3 showing the way in which the grid laterals are all bent to occupy a single plane at one side of the support rods and over a considerable distance therebetween, while Fig. 6 is a modified form of the lizing a formed half grid.

In Fig. 1, there is shown an electron discharge tube which includes an evacuated vitreous casing I0. Within the casing or envelope it there is provided a mount structure H. Between insulating spacers l2 and I4 and supported in proper relative position thereby are arranged a substantially central cathode IS, a pair of half grids I8 and 29, one on each side of cathode l6, and anodes 22 and 24 individual to the half grids l8 and 20, all together forming mount H. Cathode I 6 is coated on its exterior surface with an electron emissive material (not shown) and,

invention, utiwithin its hollow interior, is provided with a heating wire 26, by means of which the cathode i6 is heated to operating temperature, whereby electrons are emitted from the coating on the cathode. The cathode, both ends of the heater wire 26, each grid l8 and 20, and each plate 22 and 24 are connected to terminal pins 3% passing through the glass header base of the envelope l0, and by means of which circuit connections may be made to the interior elements of the tube.

Grids l8 and '29 are constructed by first winding, as shown in Figs. 3 and 4, a lateral wire 32 about a pair of support rods 33 and A conventional manner of constructing such a grid is by forming a series of spaced notches along the lateral wires 33 and 3d, winding the lateral wire 32 in said notches, and then peening over the notches to hold the lateral wire 32 in place. After the grid as shown in Figs. 3 and i is wound it is placed in a forming press, and pressed into the shape shown in the end view in 5. It will be seen that the grid lateral wire 32 at the lower side of Fig. 3 has been, in Fig. 5, pressed through between the support rods 33 and 34 to form a single grid lattice along plane It will be seen that there is now provided a grid having all of its active lateral wires in a single plane, C-G at one side of the plane in which support rods 33 and 3t lie. Ihe lateral wire 32 instead of being a large number of separate pieces, as in previous practice, actually wraps substantially completely about the support rods 33 and 34, whereby a very rigid structure is formed.

If, instead of having a planar grid such as shown in Fig. 5, it is desired to have a semicircular grid, the wound structure shown in Figs. 3 and 4 may be deformed as shown in the end view in Fig. 6. Here again, it will be noted that the grid lateral wire is still all in one piece and wraps substantially completely about the support rods 33 and 34. Thus, the full mechanical rigidity of the ordinary full wound grid is retained while at the same time, obtaining the desired space advantages of a half grid. Extensive shock tests have indicated that these apparent advantages are in fact attained in practice.

What is claimed is:

l. A half grid for electron discharge devices including a number of support rods and single continuous length of lateral wire wound about said support rods and secured to said rods, said lateral wire being formed so as to lie in a single surface at one side of said support rods, said surface being for the major part of the distance between said support rods, 21. single plane.

2. A half grid for electron discharge devices including a number of support rods and a sin gle continuous length of lateral wire wound about said support rods and secured to said rods, said lateral wire being formed so as to lie in a single surface at one side of said support rods, said surface being a portion of a cylinder having its,

center to one side of the plane in which said support rods lie.

3. An electron discharge device including within an evacuated casing, a cathode, an anode at one side of said cathode, and a grid between said cathode and said anode, said grid including a number of support rods and a single length of lateral wire space wound about said support rods, said lateral wire being doubled back around said support rods and deformed to have major portions lying in a single surface at one side of the plane occupied by said support rods.

4. An electron discharge device including within an evacuated casing, a cathode, an anode at one side of said cathode, and a grid between said cathode and said anode, said grid including a number of support rods and a single length of lateral wire space wound about said support rods and secured to said rods, said lateral wire being deformed so that every length of lateral wire between said rods lies in a single surface at one side of the plane occupied by said support rods.

5. The method of manufacturing a half grid for use in electron discharge devices which includes winding in generally cylindrical conformation, a helix of grid lateral wire about a pair of spaced parallel support rods, said lateral wire being secured to said support rods at its points of contact therewith, and thereafter deforming said grid lateral wire from said generally cylindrical conformation, so that all wire lengths between said support rods lie in a single surface at one side of the plane occupied by said support rods.

6. The method of manufacturing a half grid for use in electron discharge devices which includes winding in generally cylindrical conformation, a helix of grid lateral wire about a pair of spaced parallel support rods, said lateral wire being secured to said support rods at its points of contact therewith, and thereafter deforming said grid lateral wire from said generally cylind ical conformation, so that all wire lengths between said support rods lie in a single plane at one side of said support rods for a major part r of the distance between said support rods.

'1'. A half grid for electron discharge devices including a number of support rods and a single continuous length of lateral wire wound about said support rods and secured to said rods, said lateral wire being formed so that the lengths of wire between said support rods lie in a single surface.

3. A half grid for electron discharge devices including a number of support rods a single continuous length of lateral wire wound about said support rods and secured to said rods, said lateral wire being formed so that every length of wire between said support rods lies in a single surface at one side of the plane in which said support rods lie.

9. A half grid for electron discharge devices including a number of support rods and a single continuous length of lateral wire wound about said support rods and secured to said rods, said lateral wire being doubled back. about said support rods so that every length of wire between said rods lies in the same single surface.

10. A half grid for electron discharge devices including a number of support rods and a single continuous length of lateral wire wound about said support rods and secured to said rods, said lateral wire being doubled back about said support rods so that every length of wire between said rods lies in the same single surface at one side of the plane in which said support rods lie.

11. An electron discharge device including within an evacuated casing, a cathode, an anode at one side of said cathode, and a grid between said cathode and said anode, said grid including a number of support rods and a single length of lateral wire space wound about said support rods, said lateral wire being doubled back around said support rods and deformed to have major portions lyin in a single surface.

12. The method oi. manufacturing a half grid for use in electron discharge devices which includes winding in generally cylindrical conformation, a helix of grid lateral wire about a pair of spaced parallel support rods, said lateral wire being secured to said support rods at its points of contact therewith, and thereafter deforming said grid lateral wire from said generally cylindrical conformation, so that all of the wire lengths between said support rods lie in a single surface:

13. A half grid for electron discharge devices including a: number of support rods and a single continuous length of lateral wire wound about said support rods and secured to said rods, said lateral wire being formed so that every length of wire between said support rods lies for a substantial distance in a single surface.

14.A half grid for electron discharge devices including a. number of support rods and a single continuous length of lateral wire wound about said support rods and secured to said rods, said lateral wire being formed so that every length of wire between said support rods lies for a substantial distance in a single surface at one side of the plane in which said support rods lie.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,128,280 Arnold Feb. 16, 1915 1,630,443 McCullough May 31, 1927 1,688,991 Schwerin Oct. 23, 1928 1,958,349 Robinson May 8, 1934 FOREIGN PATENTS Number Country Date 810,903 Great Britain Apr. 24, 1929 428,478 Great Britain May 14, 1935 550,435 Great Britain Jan. 7, 1943 

